The present invention relates to electrical connectors, and more particularly to modular connectors for connecting daughter printed wiring boards to mother printed wiring boards.
In the manufacture of computers and other electronic apparatus, daughter printed wiring boards (PWBs) are commonly connected to mother PWBs by means of modular electrical connectors, typically comprising a receptacle and a header. A daughter card (or PWB) electrically and mechanically connects to a receptacle, which in turn electrically and mechanically connects to a mother card (or backplane).
Modular electrical connectors of the type mentioned above are used, for example, to connect a large number of signal wires to a PWB. Consequently, a connector is provided with a number of columns of contact holes with contact pins disposed therein. An exemplary connecter is an 8xc3x9712 connector which has 12 columns of 8 contact holes with contact pins disposed therein.
As miniaturization becomes more prevalent, the number of signal wires to be connected to a connector increases, but the dimensions of the connector itself must not increase and preferably should even decrease. This results in an increasing number of signal and ground connections in the limited space of the connector. In high-frequency applications, this results in the risk of cross talk in the signal connections.
Accordingly, to combat the risk of cross talk due to mutual EMI of the signal connections, electrical connectors are equipped with shielding to attempt to shield each signal from EMI from neighboring and nearby signals. This shielding can be a conventional mechanical shield or an electrical shield in the form of a ground line. With today""s electrical connectors, however, the current state of shielding still leaves great risk for cross talk. It is, therefore, desirable to provide an electrical connector that has enhanced shielding capabilities, yet does not significantly reduce signal density.
Stripline configurations, i.e., arrangements in which conductors in parallel in a dielectric are interposed between ground planes, are known in the art. A need exists for a way to use such configurations to reduce cross.
A header for interconnecting electrical components is provided. The header comprises at least one column of conductors interposed between ground planes, wherein the column of conductors comprises at least a first, second and third conductor. The first conductor is a ground line, the second and third conductors are signal lines, and the first conductor is electrically connected to one of the ground planes, wherein the second conductor is positioned in the column in interposed relation between said first and third conductor.
In alternate embodiments, the header for interconnecting electrical components comprises a plurality of rows and columns of signal lines, wherein at least one column comprises at least one ground line situated between two signal lines so that the ground line is coplanar with the signal lines.
A ground plane for providing at least one ground line throughout a header for interconnecting electrical components also is provided. The ground plane comprises at least one substantially vertically-oriented metal shield section for separating signal lines of adjacent columns and at least one substantially horizontally-oriented ground shield, through which a ground line that carries a ground current passes.